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Q3.1. What are the classic problems/areas to check on 911s?<- ->The 911 is a really good car but there are a few problem areas that have, at various times, plagued this particular vehicle.First, the results of an on-going survey of 911 repairs is given in the tables below. The tables are broken into Major (~$1000 and above), Not Quite So Major (less than $1000), Maintenance (ya gotta plan to do these), and Optional (fun, but not necessary to keep the car on the road). Responses.
Major.
Not Quite So Major.
Maintenance.
Optional.
Some Detailed InformationBelow is a list of some of the most notorious problems.RustRust can destroy a 911's unit-body and this can be really expensive (impossible?) to fix. Watch closely for rust, particularly with the pre-galvanized bodies (pre-1976?). Check the seams around and edges of the doors, trunk, and hood. Check the jack points and the torsion bar tubes.Heat exchangers rust along with everything else. Be careful, this can lead to carbon monoxide poisoning of your car's occupants. Many replace theirs (their exchangers, not their occupants) with stainless steel once. Chain TensionersThe timing chain is held taught by chain tensioners. The early (pre-1984) timing chain tensioners tended to wear out and suddenly collapse causing your pistons to come in violent contact with your valves. This gets expensive. The 1984 and later cars used oil- fed tensioners which solved the problem.Many early 911 owners have had their older chain tensioners replaced with Carrera tensioners. This modification requires about six hours of labor with parts costing around $300-$400 per bank of cylendars (roughly $1000). Adding carrera tensioners is even more expensive on pre-1967 engines because the updated parts don't fit correctly. Some have modified their tensioners by adding mechanical tensioner guards. These devices keep the tensioners from collapsing completely when they collapse. I have heard failure stories as well as success stories regarding tensioner guards. Worn Mechanical Fuel Injection PumpThe injection normally doesn't require too much adjustment. In around 100,000 miles, however, fuel injection pumps wear out. A worn pump manifests itself usually by running too rich beyond the control of adjustment. The pump usually costs between $800 and $1500 to be rebuilt.Many people replace their worn mechanical injection with weber carburators but purists, like me, hate to see this kind of thing happen. If you do change-out your injection, at least save it so a future owner of your car can return it to original condition. Exploding ClutchThe 911SC (1978-1983) used a rubber-centered clutch which would eventually fail and send rubber pieces sailing throughout that part of the transmission. These clutches should be replaced by a spring-centered one.Exploding AirboxThe 2.7 and 3.0 liter 911 cars use a $200 airbox that can, if the car backfires while starting, explode. For around $15, you can get a pop-off valve that is supposed to fix this problem.Puff of Blue Smoke on StartupThis is not a problem. 911s tend to have oil seep into the cylendars when they sit at rest. When the car is started, the oil burns and this gives you the puff of blue smoke. This is normal and does not, in and of itself, require any fix.Carrera 2/4 DistributorsThere's an internal belt in the distributor of the Carrera 2 and Carrera 4 cars that breaks at about 50,000 miles. Unfortunately, the fix is a new distributor at a cost of somewhere around $1000.Q3.2. So, what's all these problems I keep hearing about the 2.7 liter 911s?<- ->It's a tragic story. Porsche increased the displacement of the 2.4 without providing enough cooling and, to add insult to injury, the US models had thermal reactors (except for 1974) that got REALLY hot. The result is, among other things, head studs that pulled out of the crank case (due to thermal expansion of the cylinders) and destroyed valve trains. All of this resulted in an average engine life of about 50,000 miles (your mileage may vary -- HA! I was *waiting* to use that line).The classic 2.7 problems are mitigated in the early and late cars. The 1974 cars had no thermal reactors so those don't tend to be as bad. The 1977 cars used Dilivar studs on the exhaust side and I've heard reports of them lasting 120,000 miles. So the natural follow-on question (so natural, in fact, that I'm not breaking it out into its own question) is "can anything be done to mitigate the design flaws of the 2.7?" The answer is:
Q3.3. At what pressure and temperature ranges should my 911 operate? <- ->The sources I have checked largely agree with each other. My 2.4 Owner's Manual (it covers T, E, and S models) states that the temperature should not exceed 265 F. According to an article by Bruce Anderson. . .
"Our personal max temp while running 600 hour endurance runs on the dyna at Porsche (for non-Porsche engines but that doesn't matter) was I think 130 deg C which is 266 F. 120 C was more typical but it could get up to 130. Of course we changed oil regularly. Modern oils can take more heat before breaking down than the stuff 20 years ago. You really WANT the oil to get above 100C, 212 F, to get the condensate water out of it."Pete Albrecht, PLAlbrecht@aol.com, "Re: Oil temps, continues", 960627183812_423165721@emout17.mail.aol.com On oil pressure, it should be between 10 and 15 pounds per thousand RPM. My Owner's Manual states that pressure should not drop below 70PSI at 5500 RPM. Moreover, the oil level should never drop below the minimum mark on the dip stick (remember to check the oil on level ground while the engine is running and the temperature is over 180 F). Q3.4. Where can I find a car seat for the rear seats of my 911? <- ->This is a difficult problem to which there seems to be no perfect solution. When our kid was born (1987), we had a car seat made by Kolcraft; it seemed to fit okay into the skinney rear seat but it hung over the front of the seat a little. In retrospect, this was probably unsafe. Thank heaven that I never had this tested.Several people have found that Porsche makes a seat to fit into the rear of a 911 but doesn't ship it to the United States. This seat requires a 3-point seat belt (a lap belt PLUS a shoulder harness). I can't state strongly enough that you don't what to compromise where safety is concerned. I don't know why Porsche doesn't send their seats to the US, but is this a chance you're willing to take with your child? Mark Salvetti describes the seat: It consists of four pieces, each sold separately: a seat bottom, a backrest (that straps to the seat bottom), a shield or table that the seatbelt passes through and secures the child across the thighs and midsection, and an insert that fits under the seat bottom (928/944/968 only).Mark Salvetti. mark_salvetti@ABBSMTP.abb.com "Re: 911 Baby Seats (long)", 26 Jun 96. Message-Id: <9605268358.AA835827015@ABBSMTP.ABB.COM> Mark also said that you can buy the seat for 175 British Pounds from AFN, a dealership in Cheswick, England. You can reach them at 011-44-1-81-742-7700. Todd Cohen found another partial fit: For the few times that I drove my daughter around in the 911, I was able to use the existing car seat that I had. I had a Century 2600 seat, to install it in the 911 I removed the rear cross bar, by removing one bolt. This allowed the seat to fit in the cupped rear seats.Todd Cohen. TODD.COHEN@rdd.com "911's and Baby Seats", 25 Jun 96. Message-Id: <0013600001837344000002*@MHS> Q3.5. Any other places I can look for 911 info? <-I know nothing about alignment but you can check out Mike Piera's web page for his take on this.There's also a bunch of useful information at the Poor Man's Porsche site. References.Porsche 911 Performance Handbook, Bruce Anderson, Motorbooks International, 1987Guide to Purchase & DIY Restoration of the Porsche 911, Porter and Morgan, Haynes Publishing, 1988 The 911 and 912 Porsche, a Restorer's Guide to Authenticity, Dr. Brett Johnson, Beeman Jorgensen, Inc., 1988, 1991 Original Porsche 911, Peter Morgan (et.al.), Bay View Books, 1995 Illustrated Porsche Buyer's Guide, 2nd Edition, Dean Batchelor, Motorbooks International, 1983, 1986 Road & Track Porsche, CBS Magazines, 1988 Road & Track Porsche, CBS Magazines, 1990 New For '95, Road & Track, October 1994, Hachettte Filpacchi Magazines, Inc, 1990 Miscellaneous Articles, lance_keigwin@engtwomac.Synoptics.COM, mpardo@itsa.ucsf.EDU, 911 #1, Excellence, November 1994, Don Hollway The Used 911 Story, Peter Zimmerman, PMZ Publications, 1993
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